The Hardy Boys, brothers Frank and Joe Hardy, are fictional characters who appear in a series of mystery novels for young readers. The series revolves around teenage amateur sleuths, solving cases that often stumped their adult counterparts. The characters were created by American writer Edward Stratemeyer, the founder of book packaging firm Stratemeyer Syndicate. The books were written by several ghostwriters, most notably Leslie McFarlane, under the collective pseudonym Franklin W. Dixon. The Hardy Boys have evolved since their debut in 1927. From 1959 to 1973, the first 38 books were extensively revised to remove social and ethnic stereotypes, modernize content, and shorten the books. A new Hardy Boys series, the Hardy Boys Casefiles, was created in 1987, and featured murders, violence, and international espionage. The original "Hardy Boys Mystery Stories" series ended in 2005. A new series, Undercover Brothers, was launched the same year, featuring updated versions of the characters who narrate their adventures in the first person. Undercover Brothers ended in 2012 and was replaced in 2013 by The Hardy Boys Adventures, also narrated in the first person. Through these changes the characters have remained popular; several new volumes are published each year, and the adventures have been translated into over 25 languages. The boys have been featured in five television shows and several video games, and have helped promote merchandise such as lunchboxes and jeans. Critics have many explanations for the characters' longevity, suggesting that the Hardy Boys embody wish fulfillment, American ideals of boyhood and masculinity, a well-respected father paradoxically argued to be inept in the later books, and the possibility of the triumph of good over evil. On January 1, 2023, the original editions of the first three books entered the public domain in the United States. Under current copyright laws, the revised editions will not be in the public domain in the United States until 2054. Source: Wikipedia (en)